JIWIRE is a searchable online directory of public WiFi (802.11b and other compatible standards) wireless Internet access points. Also accessible on your PDA via AvantGo or by WAP-enabled cell phones, the directory currently lists over 20,000 "hotspots" in 46 countries.

A similar service is provided by nodedb.com, which also lists publicly accessible WiFi hotspots around the world but with an emphasis on (though it is not limited to) free community networks.

A quick comparison of the two directories showed that each contains at least some listings not held by the other, so it might pay to search both for any given location.